Giant clam

The giant clam, which inhabits the Western Pacific Ocean, is the largest living bivalve: it can exceed 120 cm in length and 200 kg in weight. It seems that the oldest records on this species are due to a Venetian navigator of the sixteenth century, Antonio Pigafetta. The food of these huge molluscs is only partly made by particles filtered out from the water. Most of their nutrition supply, in fact, is provided by photosynthetic microorganisms that live in symbiosis with the clam, hosted within its soft tissues.